Telephone



(No Model.) 2Sheets-Sheet 1.

. E. M. HARRISON.

TELEPHONE.

No. 476,200. Patented My 31, 1892..

(No Mode.) 2 Sheets-Sheet 2. E. M. HARRISON. TELEPHONE.

No. 476,2oo.

UNITED STATES PATENT DEEICE- EDWARD M. HARRISON, OF FORT SMITH, ARKANSAS.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 476,200, dated May 31,1892.

Application tiled August 9 1890.

To a/ZZ whom it may concern: Be it known that I, EDWARD M. HARRISON, a citizen of the UnitedStates, residing at Fort Smith, in the county of Sebastian and State of Arkansas, have invented certain new and useful Improvements in Electric Telephony, of which the following is a specification.

This invention relates to an electr-ic telephone in which are utilized the well-known galvanic current of 1786 and Faradays induced current of 1837 by means ot' my improved phonetic transmitter, my phonetic motor or receiver, my improved switch device or battery cut-out, and certain details of construction, as will be hereinafter fully described.

The object of my invention is to make the telephone-case as strong, compact, durable, and easy of access to its interior as possible; to improve the Reis and Hughs phonetic transmitter by providing a diaphragm of a new and improved shape and a separate frame supporting the pendent electrodes and said diaphragm independent of each other, so as to facilitate the instantaneous vibrations of the diaphragm, thereby leaving the extreme ends and edges'of said diaphragm free to vibrate; also to reduce the resistance of the flow of the galvanic current through the phonetic transmitter to the minimum; to provide an improved Faradic electric generator or induction-coil; to provide a new and improved electro-phonetic motor or receiver; to provide an improved cut-out or switch, and certain details of construction for connecting my electrical devices one with the other to form an operative combination, as hereinafter described.

The matter constituting my invention will be defined in the claims.

I will now particularly describe my improvements in the telephone by reference to the accompanying drawings, in whicht Figure l represents a front elevation of the telephone box or case with the doors thrown open and showing the back of the phonetic transmitter secured to the front door, the magneto-bell coils secured to the upper door, the induction-coil in the upper part of the case, the magneto-generator in the lower part of the case, the switch secured to the left-hand seria No. 361,599. (No man.)

side of the case and the phonetic motor or receiver hung on the switch-bar. Fig. 2 represents a diagrammatic view ofthe parts of my telephone arranged for conveniently exhibiting their construction and electrical connecnetic motor or receiver having the diaphragm resting at its edges or corners on the top of the case. Fig. 6 represents a front view of the frame for holding the phonetic transmitter diaphragm. Fig. 7 represents a front view of the wooden phonetic diaphragm having the transverse wooden bridge and carbon rail or hammer in proper position thereon.

Similar letters of reference designate corresponding parts in the different figures of the accompanying drawings.

The inclosing telephone box or case A is composed of a back board D, which projects up above the top of thebox a short distance for the purpose of receiving the binding-posts of the line-wires and any suitable form ofV lightning-arrester and of suitable sides, top, and bottom Wooden walls. The upper front corners of the side walls are cut off diagonally to provide for arranging the upper door B in an inclined position, as shown in Fig.. 2, and t said dooris united to the top of the case by hinges a. The front of the case below the inclined door B is closed by the vertical door C, which is joined to one side of the case by hinges c', as shown in Fig. l.

The front edge of the door B is rabbeted to form au angular recess b, adapted to receive the upper angular edge of the lower door C and make a tight joint therewith for excluding the dust, as shown in Fig. 2. In

.closing the case, door B is first shut down and then door C is closed and locked, with its upper edge fitting in the recess b, thereby holding the upper door tightly in place. When the doors B and C are thrown open, free access is given to all the mechanism in the IOO interior of the case, so that any part may be readily repaired or adjusted when required.

The ringer T, provid ed with bell-coils tt, is secured to the under side of door B, as shown in Figs. l and 2.

My phonetic transmitter, arranged in a suitable frame, is secured to the inside of door C, and such door is provided "with the conical mouth-piece c, just in front of the transmitting diaphragm, as shown in Fig. 2.

For the purpose of supporting my phonetic transmitter I provide a trame E, composed ot` the parallel side bars E and the cross-bars E E at top and bottom. To the upper ends of th'e side bars E of the frame are secured.

the two brackets' e e, which are perforated transversely for receiving and holding the metal pivotal rod e', which pivotallysupports the pendent electrodes G. are provided withtransverse holes near their upper ends and the pivotal rod e is passed through such holes and through the holes in the brackets e. Two rubber cushions h 72, are glued either to the cross-bars at the top and bottom of the frame or to the under side of the diaphragm F for permitting the free and ready vibration of the diaphragm. On the bracket e next to the hinge I secure a Washer e for making electrical connection with the metallic hinge and thence to the induction-coil.

e for making electrical connection to the hinge and thence through the binding-postI ter is composed of a single piece of thin wood or its equivalent, about the twenty-fourth of anA inch thick and of a peculiar elliptical shape, having elongated portions y y at the ends of the long axis of the ellipse or at the arches of the ellipse, as shown in Figs. l and `7. A transverse wooden bridgef is secured y to about the middle portion of the diaphragm, and has securedA to its upper surface the carbon-rod or hammer-electrode g, upon which rests the pendent anvil-electrodes G, as shown in Figs. l and 2. At one end of the carbon electrode g there is attached one of the primary wires from the binding-washer e, which .is in electrical connection with the battery.

The diaphragm F is lightly supported in its frame with its elongated ends y y resting on the rubber cushions h', and is held in position by two thin springs 7L at top and bottom, which springs are secu red at their ends to the frame, as shown in Figs. l and G. These springs being thin and light, exert only sufticient pressure to lightly hold the diaphragm in place and do not interfere with its free vibration or motion.

By making the diaphragm of my phonetic transmitter independent of the anvil-electrodes G, the brackets e, and the frame E E', I

These electrodes On the side bar E of the frame adjacent to the hinge I secure a second wash er thereby on producing instantaneous Vibrations of the diaphragm,from whatever cause, give the maximum motion to the lower ends of the anvil-electrodes and the minimum motion to the upper ends thereof. I claim this to be a great advantage over any of the Hughs transmitters, in which the anvil and hammer electrodes are bothmounted on the diaphragm and in Which the motion given to both ends of the anvil-electrodes is consequently alike and at the same time.

It is evident that by means of my construction and arrangement of the diaphragm, so as to be independent ot' the anvil-electrodes and the brackets which support them, such diaph ragm is much more sensitive and freer to vibrate by slight phonetic impulses, and there fore acts most effectively through the medium of its transverse rod or ham merelectrode upon the anvilelectrodes G. The carbon electrodes G hang from their pivotal rod e nearly perpendicular, with their lower ends lightly resting on the carbon-rod electrode g, making a very loose connection between the hammer and anvil electrodes, which can therefore be easily put in motion by the least vibration of the diaphragm. The air put in motion on entering the case through the conical mouthpiece escapes above and below the lateral arches of the elliptical diaphragm, and therefore there does not occur rebounds of the air, which produce overtones and prevent the free and instantaneous vibration of the diaphragm. These two separate and distinct currents are used on two separate and distinct circuits. The short circuit l 2 is a local circuit, which the galvanic current iows over,

passing from the battery X to the switchsprings 7c Z, and thence to the induction-coil H, thence to the transmitter-electrodes G g, and thence back to the batte-ry X. rlhe long circuit begins at the ground-wire 3 and passes thence to the binding-post c', thence on line 3 to binding-post w, thence to the receiver I), Fig. 3, thence back to binding-post w', thence to the secondary coil ofthe induction-coil Il, thence out on line 4 to switch-spring Z, up

`switch-bar M to spiral spring 0 or the escutcheon n, thence to binding-screw o', up

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line 4 to binding-post e', and out on line 4 to a kindred instrument.

The induction-coil is not of the ordinary experimental coils. Its general make-u p is materially changed.

The primary coil K is wound on a Wooden spool I, havin ga three-eighth s-i uch hole lengthwise through its center, which is illed with soft-iron wires or rods i the fulllength ot the spool. The primary coil K is composed of three layers ot' No. 2O silk insulated copperwire, and next to this copper-wire coil is one or two layers of paper wrapped to the thickness of about the one-twenty-fourth of an inch. On top of this paper is placed a single layer of either circular or longitudinal No. 2U softiron wires i', side by side, until the circumered therewith. placed another layer or two of thin wood or of, my induction-coil.

r several hundred windings.

,My electro-phonetic motor or receiver is shown in the sectional views, Figs. 3, 4, and 8.

The receiver-case is composed simply of a' wooden or hard-rubber circular box l?, like a short cylinder, with two wooden bottoms pp' secured thereto, and an ear-piece J secured to the top. InternallyT it is provided with two electro-magnets Q Q', fastened to an ironl `heel-piece q by screws or rivets, and with the permanent magnet R, fastened between the two electro-magnets by screws or rivets to the 3 samcheel-piece q. The permanent magnets and the electro-magnets are exactly of the same length, and the electro-magnets are wound with very fine insulated copper wire theirfull length, but not on their upper or outer ends. A thin ferrotype-plate r, a fraction smaller in diameter than the inside diameter of the case, is fastened at its center with a screw to the permanent magnet, as shown in Fig. 4,.whereby the plate is magnetized by direct contact.

Fig. 8 represents an electro-phonetic motor similar to the one shown in Fig. 4 and differing therefrom only in having the ferrotypeplate 'r raised just a fraction above the magnets and resting at its'edges or corners on the top of the case, making a very valuable receiveror electro-phonetic motor. The adjusting-screws s sfor the electro-magnets are covered by the cap or outside bottom p of the receiver to keep moisture or perspiration of the hands from rusting them. Vhen the instantaneous alternating flashes or currents of electricity from the induction-coil I-I reach the receiver, they pass through the coils Q Q', and

therefore exert a magnetic force upon the ferrotype-plate r. \Vhen these instantaneous hashes or currents in the coils are in such a direction as to assist the power of the steelmagnet R, the ferrotype-plate r is drawn nearer, and when it is in the opposite direction, and so opposes this attraction, the plate r moves farther away. The succession of alternating currents or flashes of electricity therefore produce instantaneous vibrations in the ferrotype-plate rsimilar to the instantaneous starts and stops of the Wooden transmitter diaphragm F, so that the sounds emitted by the receiving ferrotype-plate fr are similar to those sounds actuating the transmitter. Frein this it will be seen that the transmitter by its instantaneous vibrations acts as a generator, converting the instantaneous starts and stops or mechanical energy of the diaphragm F into induced or Faradic electrical energy,wl1ile the receiver acts as an electro-phonetic motor, converting electrical energy of the main line into mechanical vibrations or instantaneous starts and stops of the ferrotype-plate r, producing the tones and sounds of the transmitter. The tones and sounds themselves, it will be noticed, are not `transmitted from one point to the other.

In order to save the battery when not in. use, Iprovide at some convenient part of the primary circuit a cut-out or switch M j la Z, the form which I prefer on account of its simplicity and trustworthiness in these connections. It consists of a long metal bar lVLhaving ahook fm, at its outer end and at its` inner end a thin horizontal piece of metal m tempered very hard. The bar M is pivoted near its inner endto the socket n of the escutcheon N. The upper part of the escutcheon is elongated in the form of a tube or cylinder rn, which contains a stiff spiral spring o, secured at the top by the bindingscrew o' to the wall of the case and engaging at its lower end with switch-bar M, and serving to pull the hook end of said bar up when the weight is removed therefrom.` The ground connection 3 of the line-wire is made `fast to the upper end of the escutcheon by binding-screw o', giving three easy courses for spring to the switch-bar M; second, from the binding-screw o down the escutcheon to the switch-bar M at its junction near the spring; third, down the back of the escutcheon to the pivot j', and thence through bar M to either of the switch-springsj, la, or Z.-

The switch-springs 7c Z represent the termi n als of the primary and line circuits. If the receiver is removed from hook m, the spiral spring o will raise bar M, thereby `shifting the metal contact-piece 'm' from spring j to springs 7.: l, thus cutting out the magneto bellringer T and connecting into circuit the battery X to the phonetic transmitter and the phonetic motor or receiver P to the line-wire e.

In order to call a person to a kindred telephone at a distance, and the switch-bar being down, as shown in the drawings, the crank of the generator S is given a few turns, producing a current of electricity, which flows out over circuit 5 through the switch, thence on main line 4:, thereby ringing the bell of a kindred telephone, then through the return or ground circuit 3 to binding-post e', thence through circuit G to the bell-coils t t, thus ringing bells u u, and finally down circuit 6to the generator S. 4

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

l. A telephone-case provided with a fixed top piece, an upper inclined door hinged at at its inner edge to said top piece and having a rabbeted or recessed outer edge, and witha front lower door hinged to one of the side walls of the case and itting at its top inner edge into the rabbet of said inclined door,

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provided with a loWer door C, fitting at its i upper edge into the rabbet of door B and having secured to its inner side the phonetic transmitter, substantially asv described.

3. In aphonetic transmitter, thediaphragm having an elliptical shape, in combination with means'for supporting it and leaving its edges free, substantially as described.

4. In a phonetic transmitter, thediaphragm of an elliptical shape, with narrow extensions j of a swinging metallic bar or lever having secured to its inneruend a thin horizontal metallicy bar, an esc-utcheon having an upper cylindrical end, and a socket n', having a pivat the ends of the long axis, in combination with supporting devices, the edges of the diaphragm being left free, substantially as de'- scribed.

5. In combination w ith a frame, an elliptical diaphragm having extensions at the ends of its long axis resting on the frame and supporting-springs bearing on said extensions, substantially as described.

6. In combination with a frame, an elliptical diaphragm, cushions interposed between its ends and said frame, and supporting-springs I scribed my'nanl'e.

bearing on the ends of the diaphragm above said cushions,- substantially as described.

7. In combination with a frame, an elliptical diaphragm resting at its ends on the frame and having a transverse bridge and carbonrod` electrode, and springs adapted to hold the diaphragm in the frame, substantially as described.

t combination With the elliptical diaphragm supported at its ends in said frame and pro'- vided with a transverse bridge Vand carbonf rod electrode in contact With said pendent i electrodes, substantially as described.

9. The phonetic motor or receiver having two electro-magnets Wound' their full length ,i and a permanent magnet between, all being of the. same length and secured to a soft-iron heel-piece, adj listing-screws bearing on said l heel-piece, a ferrotype diaphragm supported normally o-ut of contact With the ends of the electro--nuagnets,` and an inclosingcase', all comi bined substantially as described.

1.0. The combination, in a telephone-switch,

otal eye, a strong spiral spring in said cylindrical end for the purpose of pulling the switch-lever up, said bar being pivotally connected to said socket, three liat springs to make the different connections with the-horizontal bar as the switch-lever is moved up and down, substantially as described.

In testimony whereof I have hereunto sub- EDWARD M. HARRISON.

Witnesses:

A. H. BoLEs, FRED TITGEN. 

